Reactivity of (Dicarboxamide)M(II)-OH (M = Cu, Ni) Complexes: Reaction with Acetonitrile to Yield M(II)-Cyanomethides.

The complexes (BuN)(LM(II)-OH) (L = 2,6-dimethylphenyl-substituted pyridine(dicarboxamide); M = Cu or Ni) react with CHCN to yield (BuN)(LM-CHCN), novel cyanomethide complexes that were fully characterized, including by X-ray crystallography. These conversions contrast with the usual reactions of metal-hydroxide complexes with nitriles, which typically involve attack at the nitrile carbon and formation of amides or carboxylic acids. Kinetic studies (M = Cu) revealed a first-order dependence on the complex and a kinetic isotope effect ((CHCN)/(CDCN) of 4.

Rapid C-H bond activation by a monocopper(III)-hydroxide complex.

One-electron oxidation of the tetragonal Cu(II) complex [Bu(4)N][LCuOH] at -80 °C generated the reactive intermediate LCuOH, which was shown to be a Cu(III) complex on the basis of spectroscopy and theory (L = N,N'-bis(2,6-diisopropylphenyl)-2,6-pyridinedicarboxamide). The complex LCuOH reacts with dihydroanthracene to yield anthracene and the Cu(II) complex LCu(OH(2)). Kinetic studies showed that the reaction occurs via H-atom abstraction via a second-order rate law at high rates (cf.

Reactions of Ph3Sb═S with copper(I) complexes supported by N-donor ligands: formation of stable adducts and S-transfer reactivity.

In the exploration of sulfur-delivery reagents useful for synthesizing models of the tetracopper-sulfide cluster of nitrous oxide reductase, reactions of Ph(3)Sb═S with Cu(I) complexes of N,N,N',N'-tetramethyl-2R,3R-cyclohexanediamine (TMCHD) and 1,4,7-trialkyltriazacyclononanes (R(3)tacn; R = Me, Et, iPr) were studied. Treatment of [(R(3)tacn)Cu(NCCH(3))]SbF(6) (R = Me, Et, or iPr) with 1 equiv of S═SbPh(3) in CH(2)Cl(2) yielded adducts [(R(3)tacn)Cu(S═SbPh(3))]SbF(6) (1-3), which were fully characterized, including by X-ray crystallography. The adducts slowly decayed to [(R(3)tacn)(2)Cu(2)(μ-η(2):η(2)-S(2))](2+) species (4-6) and SbPh(3), or more quickly in the presence of additional [(R(3)tacn)Cu(NCCH(3))]SbF(6) to 4-6 and [(R(3)tacn)Cu(SbPh(3))]SbF(6) (7-9).

Mechanistically inspired design of Fe(III)-TAML peroxide-activating catalysts.

Recent broad-ranging mechanistic studies of FeIII-TAML peroxide activators enable a strategy for designing catalysts with improved (i) hydrolytic and (ii) operational stabilities, (iii) faster activation of H2O2 and other peroxides, and (iv) a pH of highest activity closer to 7. Combining all items of insight leads to [Fe{1-NO2C6H3-3,4-(NCOCMe2NCO)2CF2}(OH2)]- (1a) which exhibits the most desirable technical performance in its class.